Before washing, I fasten all the buckles as if I were wearing it.
Turn it inside out.
Wash by itself in cold water.
Remove from washer.
Turn back outside out.
Shake a bit to hang pleats back.
Place on plastic hanger (I use 4 of the removable plastic jaws)
Straighten out pleats and apron.
Air Dry.
I use a steamer (carefully) to sharpen the pleats up and smooth the apron.

BTW, does anyone have advice on de-fanging the buckle tongues as they can bite a bit? Fine tooth file maybe?